南美水仙组培外植体再生体系建立中的关键技术研究

以南美水仙的鳞茎、叶片和叶柄等营养器官作为外植体进行组织培养,着重研究南美水仙最佳外植体、最佳培养基配方的关键技术.研究结果表明,诱导的最佳培养基为MS 6-BA 2.0mg/L NAA 3.0mg/L,培养45d可获得较多的小鳞茎.外植体分化能力的研究表明,南美水仙的不同类型外植体能力大小为:鳞茎＞叶柄＞叶片;从鳞茎的不同部位来看,基部鳞茎盘＞内层鳞片下部＞外层鳞片下部＞内层鳞片上部＞外层鳞片上部.     

膜荚黄芪愈伤组织诱导及植株再生体系的建立

为了建立膜荚黄芪组培快繁技术体系,本研究以膜荚黄芪无菌试管苗的下胚轴为外植体,探讨不同激素种类及其浓度配比对愈伤组织诱导率、丛生芽诱导率、再生苗生根率的影响,筛选适宜的培养基配方。结果表明:膜荚黄芪愈伤组织最佳诱导培养基是MS+6-BA 0.5 mg/L+2,4-D 2.0 mg/L,愈伤组织诱导率达86.4%,丛生芽分化的最佳培养基是MS+6-BA 1.0 mg/L+NAA 0.3 mg/L,丛生芽分化率最高达91.6%,再生苗最佳生根培养基1/2MS+IBA 0.5 mg/L+IAA 1.0 mg/L,生根率最高达62.6%。本研究建立了膜荚黄芪组培快繁技术体系,为其种质资源保存及开发利用提供了有力的技术支撑。     

火龙果花药培养诱导胚性愈伤组织及遗传稳定性

成年态火龙果茎段诱导的愈伤组织再分化较困难,进而影响到遗传转化效率。以红皮紫红肉的"紫红龙"火龙果花药为外植体,研究了小孢子不同发育时期、低温预处理时间、不同植物生长调节剂及浓度配比对花药诱导胚性愈伤组织的影响。结果表明,小孢子发育处于单核初期至单核靠边期的花药,其愈伤组织诱导率最高可达23.9%,但未能诱导出胚状体;而4℃低温预处理48 h,愈伤组织的诱导率可达32.8%;最适花药愈伤组织诱导的培养基为MS+2.0 mg/L 6-BA+1.0 mg/L 2,4-D+60 g/L蔗糖,诱导率为37.4%,胚性愈伤组织为黄绿色、致密状,外表有颗粒状突起。愈伤组织增殖培养基以MS+0.4 mg/L TDZ+0.8 mg/L KT效果较好,增殖系数达9.1倍以上。愈伤组织再分化培养基为MS+0.4 mg/L TDZ+0.5 mg/L 2,4-D+0.6 mg/L NAA时,愈伤组织再分化率达36.7%。通过火龙果花药诱导出愈伤组织,增殖获得大量胚性愈伤组织,再分化形成不定芽,经SRAP分子标记检测遗传性一致,能为火龙果基因工程育种和种苗快速繁育提供新的途径。     

‘凤丹’牡丹胚芽愈伤诱导及不定芽的分化

为提高‘凤丹’牡丹胚芽愈伤组织的诱导率及不定芽的分化效率,本研究以‘凤丹’牡丹种子为试验材料,对种胚愈伤诱导及不定芽分化的培养基配方进行添加与不添加2,4-D的对比试验。结果显示,诱导胚愈伤的最佳培养基为MS+1.0 mg/L NAA+1.0 mg/L 6-BA,诱导率达33.33%;诱导不定芽分化的最佳培养基为MS+0.2 mg/L NAA+1.0 mg/L 6-BA,诱导率达65.33%,表明在没有2,4-D添加的培养基中能获得更高的‘凤丹’牡丹胚芽愈伤诱导率及更多的不定芽。本研究结果可为‘凤丹’牡丹的组培和快繁技术提供一定的技术指导。     

崇明水仙花序轴诱导试管球及优化增殖体系的研究

以崇明水仙花序轴作为外植体进行试管球的诱导,并在培养基中利用不同浓度和配比的激素、蔗糖及活性碳(AC),通过对试管球的直径和增殖率的分析,研究激素、蔗糖和活性炭对试管球增殖的影响。结果表明：（1）崇明水仙花序轴诱导试管球的最佳激素配比为BA 10 mg/L+NAA 5 mg/L,能得到较高的诱导率,有效诱导率达到171.3%。（2）试管球增殖的最佳激素配比为BA 5 mg/L+NAA 1 mg/L+蔗糖40 g/L,增殖率为175.0%,小球直径可达0.41 cm。（3）提高蔗糖浓度,有利于试管球的增殖和膨大,但浓度需控制在一定范围内,以40 g/L为宜。（4）AC对试管球的直径影响不大,并显著降低试管球的增殖率,应尽量避免添加。     

钩藤愈伤组织的诱导与植株再生

为了建立钩藤愈伤组织诱导与植株再生体系。以药用植物钩藤[Uncaria rhynchophyllai (Mip.)Jack]嫩茎、嫩枝、嫩叶为外植体,通过优化激素组合,进行愈伤组织诱导和分化、幼苗生根和移栽,初步建立了钩藤愈伤组织诱导和植株再生体系。结果表明,以钩藤嫩枝作为外植体出愈情况较好,污染率低,继代后愈伤组织生长快。培养基成分为WPM+2.0 mg/L 2,4-D+0.5 mg/L 6-BA较适宜愈伤组织的诱导和增殖,诱导率可达83.3%。培养基成分为WPM+2.0 mg/L KT+0.2 mg/L NAA能分化出芽,愈伤组织率分化率达到82.3%;而1/2WPM+1.0 mg/L IBA适宜于试管苗生根,生根率达92.0%。以钩藤嫩枝为外植体诱导获得了质量良好的愈伤组织,并成功再生成植株,结果的获得可为解决钩藤人工栽培过程的资源和品质问题以及进行细胞培养和分子遗传改良奠定基础。     

金边阔叶麦冬的组培快繁技术研究

旨在研究金边阔叶麦冬的组织培养与快速繁殖技术。分析了植物生长调节剂对金边阔叶麦冬地下茎芽和叶片愈伤组织诱导、芽分化及试管苗生根的影响。结果表明:MS+BA 1.0 mg/L+NAA1.0 mg/L为地下茎芽诱导愈伤组织最佳的培养基,诱导率达100%;MS+BA 1.0 mg/L+NAA 0.5 mg/L为叶片诱导愈伤组织较为理想的培养基,诱导率为52%。地下茎芽形成的愈伤组织其芽诱导率、芽增殖倍数明显高于叶片,诱导率高者达100%,增殖倍数高者为4.6。金边阔叶麦冬试管苗生根的较为合适的培养基为1/2MS+IBA 0.5 mg/L和1/2MS+IAA 0.25 mg/L,生根率达100%,平均生根数量在5根以上。试管苗移栽苗成活率达90%以上。     

不同激素和浓度对夏天无愈伤组织诱导的影响

以夏天无块茎、芽及叶柄作为外植体,采用不同激素浓度配比对夏天无进行愈伤组织诱导的研究,摸索夏天无组培快繁的条件.结果表明:(1)对夏天无块茎愈伤组织诱导效果较好的激素种类及浓度配比是1/2 MS +6-BA(2 mg/L)+NAA(1 mg/L);平均诱导率达59.38％,形成愈伤组织的时间约20d,但后期愈伤组织未分化出芽.(2)对夏天无的芽进行愈伤组织诱导研究表明,效果较好的激素种类及浓度配比是1/2 MS +6-BA(3.5 mg/L)+ NAA(0.1 mg/L);平均诱导率为100％,愈伤组织7d左右形成,且后期大多分化出芽.(3)对夏天无叶柄愈伤组织诱导效果较好的激素种类及浓度配比是1/2 MS +6-BA(3 mg/L) +2,4-D(2 mg/L);平均诱导率仅为13.89％,且后期愈伤组织未能分化成芽.     

天冬组培快繁技术体系的研究

为确定最佳的外植体消毒方式和最适宜的诱导、分化和生根培养基,以内江天冬茎段为外植体,研究消毒时间、培养基及生长素对愈伤组织诱导、分化及组培苗生根的影响。试验结果表明,选取天冬茎段作为外植体时,0.1%氯化汞消毒处理的最佳时间为8 min,污染率为13.33%、死亡率为8.89%、存活率为77.78%。适宜愈伤组织诱导的培养基是1/2 MS+6-BA 1.0 mg/L+NAA 0.5 mg/L+蔗糖30 g/L+琼脂粉6 g/L,诱导率为72.2%,愈伤组织生长势强;适宜愈伤分化的培养基是MS+6-BA 1.0 mg/L+NAA 0.2 mg/L+蔗糖30 g/L+琼脂粉6 g/L,分化率达到82.2%,生长势较强;适宜组培苗生根的NAA质量浓度为2 mg/L,生根率可达86.7%,根系正常、生长迅速。通过研究,建立了天冬组培快繁技术体系,为保护天冬野生资源、解决优质种苗紧缺及实现规模化种植提供了科学依据和技术支撑。通过研究四川内江天冬组织培养的适宜条件,构建其组培快繁技术体系,以满足对优质种苗的需求,为天冬种质资源保护及可持续利用开辟新途径,为天冬产业化开发提供技术支持和科学依据。     

北川花魔芋愈伤组织与试管微球茎离体诱导研究

为解决我国地理标志性农产品北川花魔芋良种繁育体系的缺乏、种芋带病等难题,促进产业的发展,研究了不同外植体、不同激素及浓度配比对花魔芋愈伤组织诱导、试管微球茎形成的影响.结果表明:诱导愈伤组织的最佳外植体为幼嫩叶柄,在MS+ 1.0 mg/L 6-BA+0.5 mg/L NAA培养基上,愈伤组织诱导率可达48.3％;经继代培养可获得3种不同愈伤组织类型,其中Ⅲ型愈伤组织具有最佳增殖频率,增殖频率为90.8％;以Ⅲ型愈伤组织诱导产生试管微球茎时,最适培养基为MS+2mg/L 6-BA+-0.5 mg/L NAA+-5％蔗糖,培养4周后,可获得大量生长良好且带芽点的试管微球茎.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.